Was USS Oklahoma sunk by a mini-sub?

Researchers think they have found the remains of a Japanese mini-submarine that probably fired on U.S. battleships on Dec. 7, 1941.

Japanese warplanes hit, from left, the USS West Virginia, USS Tennessee and USS Arizona at Pearl Harbor. (Associated Press / December 7, 2009)

By Thomas H. Maugh II

December 7, 2009

The remains of a Japanese mini-submarine that participated in the Dec. 7, 1941, attack on Pearl Harbor have been discovered, researchers are to report today, offering strong evidence that the sub fired its torpedoes at Battleship Row.

That could settle a long-standing argument among historians.

Five mini-subs were to participate in the strike, but four were scuttled, destroyed or run aground without being a factor in the attack. The fate of the fifth has remained a mystery. But a variety of new evidence suggests that the fifth fired its two 800-pound torpedoes, most likely at the battleships West Virginia and Oklahoma, capsizing the latter. A day later, researchers think, the mini-sub's crew scuttled it in nearby West Loch.

The loch was also the site of a 1944 disaster in which six tank landing ships preparing for the secret invasion of Saipan were destroyed in an ammunition explosion that killed 200 sailors and wounded hundreds more.

When the Navy scooped up the remains of the so-called LSTs and dumped them outside the harbor to protect the secrecy of the invasion, it apparently also dumped the mini-sub's remains, which were mingled with the damaged U.S. ships.

"It's not often that a historian gets a chance to rewrite history," said marine historian and former Navy submariner Parks Stephenson, who pieced together the evidence for the television program "Nova." "The capsizing of the Oklahoma is the second most iconic event of the attack. If one submarine could get in in 1941 and hit a battleship, who knows what a midget sub could do today. Iran and North Korea are both building them. It's very worrying."

Stephenson and his colleagues have put together a convincing chain of circumstantial evidence, but it is just circumstantial, said Burl Burlingame, a journalist at the Honolulu Star-Bulletin and author of "Advance Force: Pearl Harbor."

"There is a good chance that this is the Pearl Harbor midget, but I don't think the case is closed on it," Burlingame said. "At this point, it is not hard evidence."

The two-man, 80-foot-long sub in question does not have a name of its own. Each of the five subs in the attack was carried by a conventional submarine and took its name from the mother boat. It is thus called the I-16-tou -- tou being Japanese for boat. Powered by a 600-horsepower electric motor, the sub could reach underwater speeds of 19 knots, twice as fast as many of the U.S. subs of the day.

The three pieces of the sub were found during routine test dives between 1994 and 2001 by Terry Kerby, chief pilot of the Hawaii Undersea Research Laboratory's submersibles Pisces IV and Pisces V. But Kerby and others assumed they were a part of a war trophy that had been captured by allied forces at Guadalcanal or elsewhere, towed back to Hawaii and scuttled.

Stephenson got involved in 2007 because he was looking for the fifth Japanese mini-sub.

In 1941, a crewman on the I-16 had received a radio call from the I-16-tou at 10:41 p.m. on Dec. 8 reporting the success of its mission. That indicated to Stephenson that the mini-sub had found a calm place in the harbor and hidden until the next night before surfacing and sending the call.

The crew members would have then scuttled the craft because they could not get it out of the harbor. The West Loch would have been a good location to hide, but researchers could find no trace of the boat there.

A diver who had been looking for the mini-sub suggested that Stephenson talk to Kerby, who sent him pictures of his find.

"As soon as I saw the bow section with the distinctive net cutter, I knew that we had found the fifth midget sub," Stephenson said. The Japanese navy modified net cutters on the subs for specific missions, and the one on the wreck was identical to those on the other mini-subs.

No torpedoes were found on the wreck, and evidence suggests that they were not present when the boat was sunk. A newly declassified photograph taken by a Japanese plane during the attack appeared to show a mini-sub firing a torpedo into Battleship Row. A report to Congress in 1942 by Adm. Chester W. Nimitz describes an unexploded 800-pound torpedo recovered after the battle. That's twice the size carried by the torpedo bombers.

That torpedo was apparently a dud that missed the West Virginia.

But an examination of the remains of the Oklahoma shows that it apparently had underwater damage much larger than that associated with aerial torpedoes. An underwater blast would have caused it to capsize, Stephenson said. "Otherwise it would have settled to the bottom upright," like the other sunken ships.

The 1944 disaster at West Loch occurred on May 21 as the Navy was preparing to invade the Mariana Islands in Operation Forager. The Navy clamped a top-secret classification on the incident to keep it from the Japanese, and few records are now available. What is known is that it was crucial to clear out the debris because the loch was by then the site of an ammunition dump.

Records from the salvage ship Valve showed that it was brought into the loch during the cleanup and its 250-ton crane was used for an undisclosed reason. Stephenson thinks it lifted the I-16-tou, but there are no records to confirm that.

The remains of the mini-sub were then dumped three miles south of Pearl Harbor along with those of the LSTs, to be found by Kerby 50 years later.

Bulkheads on the wreck are sealed, so researchers don't know whether the mini-sub crew was trapped. But a map taken from one of the other mini-subs showed the location of a safe house in Pearl City, Hawaii, suggesting the crew might have scuttled the boat and escaped.

The "Nova" episode describing the search for the I-16-tou will air Jan. 5.

But an examination of the remains of the Oklahoma shows that it apparently had underwater damage much larger than that associated with aerial torpedoes. An underwater blast would have caused it to capsize, Stephenson said. "Otherwise it would have settled to the bottom upright," like the other sunken ships.

Click to expand...

And the other torpedoes weren't underwater blasts? Not to mention that it's not any mystery why it capsized, it was hit by three airplane torpedoes along the port side, with two more airplane torpedoes impacting after it had already rolled 40 degrees to port. It flooded too quickly to counterflood, which is what saved at least one other battleship from capsizing.

And the other torpedoes weren't underwater blasts? Not to mention that it's not any mystery why it capsized, it was hit by three airplane torpedoes along the port side, with two more airplane torpedoes impacting after it had already rolled 40 degrees to port. It flooded too quickly to counterflood, which is what saved at least one other battleship from capsizing.

even if the Minisub fired off both its Torpedos (i think they only carried 2?) its kinda academic
ya can see from this diagrm that as she was listing she was struck again, and then after she had hit the bottom another torpedo penetrated the deck, by that time she was far to far gone to counter flood

would be interesting to know if the submarine did manage to first off one of her torpedos (isnt there a photo supposdly showing the torpedo and periscope from the mini sub?) but the mini-sub alone did not sink the Oklaholma,

Wait a minute, the Japanese aircraft carried Type 91 Mod 2, 935 kg Torpedoes which is over the "800 lb" torpedoes mentioned in the article. While the Midgets carried Type 97 Torps that were 980 kg...http://www.navweaps.com/Weapons/WTJAP_WWII.htm

Poor reporting once again!

Nevertheless, it would be interesting, if indeed it was the missing 5th midget sub.

Sea yields clues to '41 attack
A PBS series reports that an underwater torpedo hit one ship

By Helen Altonn

POSTED: 01:30 a.m. HST, Dec 07, 2009

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New evidence indicating the Japanese attacked Pearl Harbor effectively from under water, as well as the air, was announced today by the "NOVA" television series on the anniversary of the 1941 attack that led the United States into World War II.

"Pearl Harbor was always seen as an aerial attack," said Parks Stephenson, lead investigator of an underwater expedition for the PBS science series, which explored the wreckage of a midget submarine discovered by University of Hawaii researchers.

Eyewitness accounts, a congressional report by Adm. Chester Nimitz, former Pacific Fleet commander, and other clues indicate the midget sub fired two torpedoes and claimed success in a radio call to the Japanese high command 12 hours after the attack, he said.

Stephenson said the accounts indicate one torpedo was fired at the USS Arizona that was a dud, but he believes another torpedo hit the USS Oklahoma.

The marine forensic historian and former U.S. Navy officer and submariner discussed the findings of the expedition in a telephone interview from his San Diego home. "NOVA" will present the new evidence and underwater footage of the Japanese midget submarine in a TV documentary, "Killer Subs in Pearl Harbor," premiering on KHET-PBS Jan. 5.

"A giant piece of the Pearl Harbor puzzle has fallen into place," Stephenson said. "This important discovery sheds light on a World War II mystery that has eluded historians for nearly seven decades."

Five Japanese "mother" submarines approached within a few miles of Pearl Harbor before the Dec. 7 battle, each carrying a Type-A, two-man, midget submarine, about 80 feet long and 6 feet wide, NOVA said.

The sophisticated midget subs were twice as fast as many U.S. subs of the times, with 600-horsepower electric motors that could propel them underwater at speeds of 19 knots (22 mph). They were capable of carrying two Type 97 Long Lance Torpedoes.

All but one of the five midget submarines were found over the years, "either destroyed, scuttled or run aground," NOVA said. "They missed the targets, failed to fire or were recovered with torpedoes intact. But historians have long puzzled over the fate of the missing sub."

Stephenson, a Lockheed Martin engineer, said the submersibles Pisces IV and Pisces V, belonging to the Hawaii Undersea Research Laboratory, found three sections of the missing sub in cruises over the past few years in the same area south of Pearl Harbor.

He accompanied Terry Kerby, HURL operations director and chief pilot, on a "validation" cruise in March. Kerby had been the first to spot the midget sub amid damaged equipment and landing craft from the 1944 West Loch explosion.

Also along as observers on the UH submersibles in March were a Japanese expert on midget subs and retired Adm. Kazuo Uyeda, the senior surviving midget submariner from WWII.

"One can conclude definitely that this was the special submarine that was used in Pearl Harbor," Uyeda said.

Stephenson said microbiologist Lori Johnston, who did extensive work on the Titanic, sunk in 1912, determined the torpedoes were fired before the sub sank because of rustlike encrustation covering the empty torpedo tubes.

A survivor of the Oklahoma described one torpedo as much more violent than others hitting the ship, he said.

"So the Oklahoma, in my eyes, is the leading candidate" for the midget submarine's torpedo. "I have a theory that if the Oklahoma had not been hit by a more powerful torpedo, it might have righted itself like the West Virginia."

As more evidence, a photo taken by a Japanese airplane during the attack seems to show the conning tower of the midget sub at the surface pointed at the Oklahoma, Stephenson said.

Nimitz described an unexploded torpedo sighted and recovered inside the harbor with an explosive charge of 1,000 pounds -- more than twice that of aerial torpedoes -- which provides "corroborating evidence that a midget sub did penetrate Battleship Row and fired upon it," said "NOVA."

U.S. veterans told "NOVA" investigators the Arizona was torpedoed from below, but "NOVA" divers who had special permission to film the hull 40 feet beneath the surface found no visible signs of a torpedo hit.

It is believed the midget sub escaped to a secluded area of West Loch, remained undetected to get off a radio call, then was scuttled by the crew to keep it out of enemy hands, Stephenson said. The fate of the crew is uncertain.

Why it was found in three sections on the ocean bottom several miles outside of Pearl Harbor was a puzzle until "top secret" information was revealed recently about an ammunition explosion that killed nearly 200 sailors and wounded hundreds more in West Loch on May 21, 1944, "NOVA" said.

"The U.S. Navy quickly and quietly cleaned up the remnants of the 1944 West Loch disaster to get the top-secret (Normandy) invasion back on track."

Stephenson said he believes the Navy found the midget sub and took it with the rest of the debris a few miles outside of the harbor and dumped it all together.

Burl Burlingame, a Star-Bulletin writer, author of "Advance Force Pearl Harbor" and a historian for the "NOVA" project, said, "The more we learn, the more mysterious it gets."

New evidence indicating the Japanese attacked Pearl Harbor effectively from under water, as well as the air, was announced today by the "NOVA" television series on the anniversary of the 1941 attack that led the United States into World War II.

COURTESY PARKS STEPHENSON
The wreckage of the last of five Japanese midget subs sent to attack Pearl Harbor on Dec. 7, 1941, was identified recently with the help of Hawaii scientists. Shown is the midsection and conning tower of the 80-foot-long, two-man vessel, believed scuttled in the aftermath of the attack.
View more photos >>"Pearl Harbor was always seen as an aerial attack," said Parks Stephenson, lead investigator of an underwater expedition for the PBS science series, which explored the wreckage of a midget submarine discovered by University of Hawaii researchers.

Eyewitness accounts, a congressional report by Adm. Chester Nimitz, former Pacific Fleet commander, and other clues indicate the midget sub fired two torpedoes and claimed success in a radio call to the Japanese high command 12 hours after the attack, he said.

Stephenson said the accounts indicate one torpedo was fired at the USS Arizona that was a dud, but he believes another torpedo hit the USS Oklahoma.

The marine forensic historian and former U.S. Navy officer and submariner discussed the findings of the expedition in a telephone interview from his San Diego home. "NOVA" will present the new evidence and underwater footage of the Japanese midget submarine in a TV documentary, "Killer Subs in Pearl Harbor," premiering on KHET-PBS Jan. 5.

"A giant piece of the Pearl Harbor puzzle has fallen into place," Stephenson said. "This important discovery sheds light on a World War II mystery that has eluded historians for nearly seven decades."

Five Japanese "mother" submarines approached within a few miles of Pearl Harbor before the Dec. 7 battle, each carrying a Type-A, two-man, midget submarine, about 80 feet long and 6 feet wide, NOVA said.

The sophisticated midget subs were twice as fast as many U.S. subs of the times, with 600-horsepower electric motors that could propel them underwater at speeds of 19 knots (22 mph). They were capable of carrying two Type 97 Long Lance Torpedoes.

All but one of the five midget submarines were found over the years, "either destroyed, scuttled or run aground," NOVA said. "They missed the targets, failed to fire or were recovered with torpedoes intact. But historians have long puzzled over the fate of the missing sub."

Stephenson, a Lockheed Martin engineer, said the submersibles Pisces IV and Pisces V, belonging to the Hawaii Undersea Research Laboratory, found three sections of the missing sub in cruises over the past few years in the same area south of Pearl Harbor.

He accompanied Terry Kerby, HURL operations director and chief pilot, on a "validation" cruise in March. Kerby had been the first to spot the midget sub amid damaged equipment and landing craft from the 1944 West Loch explosion.

Also along as observers on the UH submersibles in March were a Japanese expert on midget subs and retired Adm. Kazuo Uyeda, the senior surviving midget submariner from WWII.

"One can conclude definitely that this was the special submarine that was used in Pearl Harbor," Uyeda said.

Stephenson said microbiologist Lori Johnston, who did extensive work on the Titanic, sunk in 1912, determined the torpedoes were fired before the sub sank because of rustlike encrustation covering the empty torpedo tubes.

A survivor of the Oklahoma described one torpedo as much more violent than others hitting the ship, he said.

"So the Oklahoma, in my eyes, is the leading candidate" for the midget submarine's torpedo. "I have a theory that if the Oklahoma had not been hit by a more powerful torpedo, it might have righted itself like the West Virginia."

As more evidence, a photo taken by a Japanese airplane during the attack seems to show the conning tower of the midget sub at the surface pointed at the Oklahoma, Stephenson said.

Nimitz described an unexploded torpedo sighted and recovered inside the harbor with an explosive charge of 1,000 pounds -- more than twice that of aerial torpedoes -- which provides "corroborating evidence that a midget sub did penetrate Battleship Row and fired upon it," said "NOVA."

U.S. veterans told "NOVA" investigators the Arizona was torpedoed from below, but "NOVA" divers who had special permission to film the hull 40 feet beneath the surface found no visible signs of a torpedo hit.

It is believed the midget sub escaped to a secluded area of West Loch, remained undetected to get off a radio call, then was scuttled by the crew to keep it out of enemy hands, Stephenson said. The fate of the crew is uncertain.

Why it was found in three sections on the ocean bottom several miles outside of Pearl Harbor was a puzzle until "top secret" information was revealed recently about an ammunition explosion that killed nearly 200 sailors and wounded hundreds more in West Loch on May 21, 1944, "NOVA" said.

"The U.S. Navy quickly and quietly cleaned up the remnants of the 1944 West Loch disaster to get the top-secret (Normandy) invasion back on track."

Stephenson said he believes the Navy found the midget sub and took it with the rest of the debris a few miles outside of the harbor and dumped it all together.

Burl Burlingame, a Star-Bulletin writer, author of "Advance Force Pearl Harbor" and a historian for the "NOVA" project, said, "The more we learn, the more mysterious it gets."

1. Mini-sub engaged by USS Ward. (Found in 2002, both torpedoes still on board.)
2. Mini-sub sunk by USS Monagahan. Salvaged soon after the attack.
3. Ensign Kazuo Sakamaki's mini-sub. Abandoned and washed ashore.
4. The Keehi Lagoon mini-sub.
5. The mini-sub that attacked USS St. Louis as it left harbor. (Fired both torpedoes at the cruiser.)

There is a show that aired on the military channel that said that "No there was no torping by mini subs" and they tested the difference between a air launched and a sub-surface launched torp. Mini subs of the time had a distinct splash that followed a launch due to the weight leaving the sub.

"A survivor of the Oklahoma described one torpedo as much more violent than others hitting the ship, he said."

Confusion in times of war. Seriously getting hit by multiple torps isn't exactly conductive of knowing where they came from.

"Stephenson said microbiologist Lori Johnston, who did extensive work on the Titanic, sunk in 1912, determined the torpedoes were fired before the sub sank because of rustlike encrustation covering the empty torpedo tubes."
Ok mabey a new science but no... I don't think I'll take a microbiologst at his word on if a torpedo was fired 60 years ago or not. Looking at the titanic doesn't exactly make him the best source for this as you know... it was sunk without the giant exsplosion.

Could it of happened? Mabey. Did it? Highly doubtfuly as those things were nothing but steel coffins. The one that did get close got shot the frack up and nothing points to the mini's even getting past the patrols. :/